Boston Mayor Marty Walsh announced hours before the parade that he wouldn't participate after parade organizers and gay advocacy group MassEquality were not able to reach an agreement to allow LGBT people to march openly.

MassEquality wanted to sponsor a group of gay veterans with a banner identifying them as LGBT, but parade organizers said MassEquality had to play by their rules.

"One person wouldn’t budge on the banner so I’m not marching in the parade if people can’t express who they are," Walsh said.

For weeks Walsh worked to broker a deal between MassEquality and parade organizer the Allied War Veterans. Talks stalled and eventually stopped.

"It’s been difficult, the parade has been difficult," said Michael Dowling, who represents one of the two sanctioned groups promoting diversity.

Dowling says his group – which was allowed to march with rainbow flags – was accepted and rejected and then accepted again amid the controversy. He applauds the new mayor.

"I’m very proud of him for taking a stand on this," Dowling said. "He’s setting himself up to be a broker of peace and community and in the city that’s much needed."

South Boston resident Randy Foster, who is openly gay, also marched… along with a group of other gays. Foster doesn’t believe change can be quick or forced.

"There’s been a lot of emotion," he said. "You want to be included across a board but it’s just like when you move into a new neighborhood, you got to get to know them and take small steps.

You don’t take big leaps and expect people to accept you."U.S. Rep. Stephen Lynch, who initially said he wouldn’t march if the MassEquality wasn’t allowed, did, in the end, with one gay veteran.

Forty years ago, one of the greatest boxing matches in history took place in an unlikely setting: the capital of the Philippines. Muhammad Ali's epic win over great rival Joe Frazier in 1975 became known as the "Thrilla in Manila."